Common foods high in lysine include fish, most meats including beef and poultry, and dairy products like cheese and milk. Plant-based foods that are good lysine sources include soy foods, brewer's yeast, as well as some nuts and others legumes. Lysine is an essential amino acid that must be obtained from the diet because it can't be produced in the body. Most complete protein sources, such as animal-derived products, contain significant amounts of this amino acid. Lysine supplements are available, but even people who don't eat animal foods shouldn't need them.
People who eat foods derived from animals should easily get enough lysine. Poultry sources of lysine include chicken and turkey. Beef and pork products, as well as venison and lamb, are also rich in lysine. Fish and shellfish are also high in lysine, including commonly available fish like salmon, cod, and sardines. Dairy products like milk, cheese, and yogurt can also help provide adequate amounts of lysine.
Most fruits and vegetables are generally incomplete proteins and contain little lysine. One likely exception to this general rule is the avocado. Some so-called non-traditional grains contain more lysine than traditional grains like wheat. Quinoa and amaranth are two examples of such non-traditional grains that have a more complete profile of the essential amino acids, including lysine. While they may not be as commonly available as traditional grains, they may be a useful addition to a vegetarian or vegan diet.
While animal products are generally the best foods high in lysine, vegans and vegetarians probably get enough of this amino acid. Vegetarians who eat eggs and animal products are highly unlikely to have low lysine intakes. Vegans who eat large amounts of traditional grains but few legumes are at a slight risk for lysine deficiency. Vegan foods that contain lysine include brewer's yeast and soy products, such as fresh soybeans and soy-based food like tofu and textured vegetable protein, as well as other nuts and beans.
Foods high in lysine are sometimes recommended as a way to treat cold sores caused by the herpes simplex virus, as well as genital warts caused by a related herpes virus. It is thought that, for this strategy to be successful, foods rich in the amino arginine must be avoided. Foods rich in arginine include legumes, nuts, and whole wheat products. Lysine dietary supplements, which usually contain 1,000 to 3,000 mg of lysine, may be useful in reducing recurrent cold sore outbreaks.